JPH0120973B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a die adjusting device for an extruder for adjusting thickness unevenness during extrusion molding of rubber or plastic.

[Prior art]

Generally, wire/cable sheathing or tubes are formed by extruding material between a die attached to the tip of the head of an extruder and a nipple installed inside the die. If the positional relationship is not appropriate, uneven thickness will occur.

Conventionally, adjustments to eliminate this uneven thickness have been made by applying centering bolts screwed into the heads at 90° intervals to the outer periphery of the die, and by having workers individually adjust the centering bolts. In other words, the nipple is fixed and the uneven thickness is adjusted by adjusting the radial position of the die using centering bolts.

〔problem〕

However, this method has the problem that it requires skill and time to adjust the uneven thickness because it requires manual labor. Further, it is not possible to automate thickness unevenness adjustment by linking with a thickness measuring device or a wall thickness measuring device.

[Means for solving problems]

In order to solve the problems of the prior art as described above, the present invention provides a device for adjusting the radial position of a die attached to the tip of the head of an extruder. A tapered part is formed, a taper piece is inserted between the tapered part and the inner surface of the head, and an actuator for sliding the tapered piece in the extrusion direction is attached to the head. It is something.

[Effect]

When the actuator slides the taper piece in the extrusion direction, the die is pushed by the taper piece and moves in the radial direction, making it possible to adjust the position in the radial direction. Although the amount of radial movement of the die required to adjust the uneven thickness is extremely small, the displacement of the tapered piece in the extrusion direction is converted into the radial displacement of the die by the mutual sliding of the tapered surfaces. This makes it possible to precisely make fine adjustments in the radial direction.

〔Example〕

1 to 3 show an embodiment of the die adjusting device of the present invention.

In the figure, 11 is the crosshead body of the extruder, 12 is a die attached to the tip of the crosshead body 11, and 13 is the crosshead body 11.
the nipple holder inserted from the rear end side,
14 is a nipple held at the tip of the nipple holder 13. The rubber or plastic material sent from the extruder body (not shown) is
It enters the crosshead body 11 through the inlet channel 15, is changed into a cylindrical flow around the nipple holder 13, and is then pushed out from between the die 12 and the nipple 14.

A die holder 16 is installed in front of the die 12, and the crosshead body 11 is held down by a bolt 17.
is fixed. This restricts movement of the die 12 in the extrusion direction. Tapered parts 18a to 18d (18
b, 18d are not shown). The tapered portions 18a to 18d are formed by forming a protrusion on the outer periphery of the die 12 (see FIG. 3), and making the back surface an inclined surface that rises forward (widens forward).

Further, on the inner peripheral surface of the die storage recess of the crosshead body 11, there are grooves 19a to 19d (19b and 19d not shown) in the extrusion direction (at 90° intervals) vertically and horizontally.
is formed, and the tapered portion 18 of the die described above is formed.
A to 18d are designed to fit into this groove. This also restricts movement (rotation) of the dice 12 in the circumferential direction. Further, the grooves 19a to 19d
Taper pieces 20a to 20d are inserted between the bottom surface of the die and the tapered portions 18a to 18d of the die. These tapered pieces 20a to 20d have grooves 19a
It has a flat surface in contact with the bottom surface of the die 19d and a tapered surface in contact with the tapered portions 18a to 18d of the die.

On the other hand, four actuators 21a to 21d are attached to the outer periphery of the crosshead main body 11 in correspondence with the taper pieces 20a to 20d.
The actuators 21a to 21d are actuators that move forward and backward in the extrusion direction, and can be, for example, hydraulic cylinders or those that convert rotation of a pulse motor into linear motion. Note that when installing the actuators 21a to 21d, in order to prevent heat from entering from the crosshead main body 11, a heat insulating plate 2 is installed.
2a to 22d.

The actuators of the actuators 21a to 21d and the taper pieces 20a to 20d are connected to links 23a to 23.
connected by d. Links 23a-23
d is rotatably supported by pins 24a to 24d fixed to the crosshead main body 11 at portions closer to the tapered pieces 20a to 20d than the center. In other words, links 23a to 23d are pin 2
The actuators 4a to 24d act as levers with fulcrums, and the driving forces of the actuators 21a to 21d are expanded and transmitted to the taper pieces 20a to 20d.

Next, the operation of this device will be explained. In this device, upper and lower actuators 21a and 21c and left and right actuators 21b and 21d operate in pairs, respectively. For example, when the upper actuator 21a is advanced to push in the taper piece 20a, and the lower actuator 21c is retreated to pull out the taper piece 20c, the die 12 moves upward. If you do the opposite, the dice 12 will move downward. Similarly, when the left actuator 21b is moved forward to push in the taper piece 20b and the right actuator 21d is moved back to pull out the taper 20d, the die 12 moves to the left. If you do the opposite, the dice 12 will move to the right.

In this way, the actuators 21a to 21d
By operating the die 12, it is possible to move the die 12 to any position in the radial direction, so that uneven thickness can be adjusted. In particular, in this device, the die is moved in the radial direction by sliding the taper piece, so by making the taper angle looser, it is possible to finely adjust the die in the radial direction. Furthermore, since the die 12 is moved by actuators 21a to 21d, for example, the wall thickness of the extruded molded product is measured with a wall thickness measuring device, and if there is an uneven thickness, a corresponding signal is activated. By sending feedback to Yuator, uneven thickness can be adjusted automatically.

Also, when replacing the die 12, use the bolt 1
7 and remove the die holder 16.

In the above embodiment, the tapered part of the die, the tapered piece, and the actuator are provided at 90° intervals, and the tapered piece and the actuator facing each other are operated as a pair by sandwiching the die. It is not limited to this. For example, even if the tapered portion of the die, the taper piece, and the actuator are provided at three locations at 120° intervals, the die can be moved in the radial direction. However, this method has the disadvantage that signal processing when operating the actuator becomes difficult. In addition, if uneven thickness adjustment is required in only one direction, the taper part of the die, taper piece, and actuator should be adjusted.
It is sufficient to install them in two locations at 180° intervals. Although it is uneconomical, the die position may be adjusted by providing the tapered portions, tapered pieces, and actuators at six or eight locations.

Further, in the above embodiments, the tapered portion of the die is formed by protruding the outer peripheral surface of the die, but it may also be formed by recessing the outer circumferential surface of the die.

〔Effect of the invention〕

As explained above, according to the present invention, since the position of the die can be adjusted mechanically, it is possible to automate the uneven thickness adjustment by linking with a wall thickness measuring device, etc., thereby eliminating the need for skill to adjust the uneven thickness. This can be done quickly without any problems. This not only improves the quality of the molded product, but also makes it possible to control the wall thickness more strictly, which greatly contributes to saving extrusion materials.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a die adjusting device according to an embodiment of the present invention, FIG. 2 is a front view of the same device, and FIG. 3 is an enlarged sectional view taken along the line -- in FIG. 11: Crosshead body, 12: Dice, 1
4: Nipple, 18a-18d: Tapered part, 2
0a-20d: Taper piece, 21a-21d: Actuator, 23a-23d: Link, 24
a-24d: Pin.

Claims (1)

[Claims] 1. A device for adjusting the radial position of a die attached to the tip of the head of an extruder, comprising a plurality of tapered portions formed at predetermined intervals on the outer periphery of the die; A die adjusting device for an extruder, characterized in that taper pieces are inserted between the tapered portion and the inner surface of the head, and an actuator is attached to the head to slide the taper pieces in the extrusion direction. 2. The device according to claim 1,
The taper portion, taper pieces, and actuator are provided at 90° intervals in the circumferential direction, and the opposing taper pieces and actuator are operated as a pair by sandwiching the die.